Sulfurization enhancement of FeMoO4 for electrochemical ammonia synthesis with high Faradaic efficiency in neutral media

Abstract

The electrochemical nitrogen reduction reaction is a more ecologically friendly alternative to the high-energy Haber-Bosch method for ammonia manufacturing, but was lack of efficient catalyst, especially in the neutral electrolyte. Inspired by the composition of biological nitrogenase with the elements of Mo, Fe and S, vulcanized FeMoO4 was designed as the nitrogen reduction electrocatalyst, which exhibited excellent catalytic performance and stability for nitrogen reduction reaction (NRR) in neutral media. During the NRR test, the vulcanized FeMoO4 achieved 31.93 μg h-1 mgcat.-1 ammonia production rate and high Faradaic efficiency (30.9%) at −0.39 V versus the reversible hydrogen electrode (RHE) in 0.1 M Na2SO4. The results demonstrated the viability of Fe-Mo base as an electrocatalyst for NRR and laid the path for the creation of a nitrogenase-like biomimetic electrocatalysts to achieve the effective N2 fixation.